/*
 * Copyright (c) 2010 Andrea Sacco
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Andrea Sacco <andrea.sacco85@gmail.com>
 */

#ifndef ACOUSTIC_MODEM_ENERGY_MODEL_H
#define ACOUSTIC_MODEM_ENERGY_MODEL_H

#include "ns3/device-energy-model.h"
#include "ns3/event-id.h"
#include "ns3/nstime.h"
#include "ns3/traced-value.h"

namespace ns3
{

/**
 * \ingroup uan
 *
 * WHOI micro-modem energy model.
 *
 * Basing on the Device Energy Model interface, has been implemented a specific
 * energy model for the WHOI micro modem. The class follows pretty closely the
 * RadioEnergyModel class as the transducer behaviour is pretty close to the one
 * of a wifi radio, with identical states (rx, tx, idle, sleep).
 *
 * The power consumption values implemented into the model are as follows [1]:
 *
 * Modem State   Power Consumption
 * TX            50 W
 * RX            158 mW
 * Idle          158 mW
 * Sleep         5.8 mW
 *
 * References:
 * [1] Freitag et al., The whoi micro-modem: an acoustic communications
 *     and navigation system for multiple platforms,
 *     in In Proc. IEEE OCEANS05 Conf, 2005.
 *     URL: http://ieeexplore.ieee.org/iel5/10918/34367/01639901.pdf
 */
class AcousticModemEnergyModel : public DeviceEnergyModel
{
  public:
    /** Callback type for energy depletion handling. */
    typedef Callback<void> AcousticModemEnergyDepletionCallback;

    /** Callback type for energy recharge handling. */
    typedef Callback<void> AcousticModemEnergyRechargeCallback;

  public:
    /**
     * Register this type.
     * \return The object TypeId.
     */
    static TypeId GetTypeId();
    /** Constructor. */
    AcousticModemEnergyModel();
    /** Dummy destructor, see DoDispose */
    ~AcousticModemEnergyModel() override;

    /**
     * Sets pointer to node.
     *
     * \param node Pointer to node.
     */
    virtual void SetNode(Ptr<Node> node);

    /**
     * Gets pointer to node.
     *
     * \return Pointer to node.
     */
    virtual Ptr<Node> GetNode() const;

    // Inherited methods.
    void SetEnergySource(Ptr<EnergySource> source) override;
    double GetTotalEnergyConsumption() const override;

    /**
     * Get the transmission power of the modem.
     *
     * \return The transmission power in Watts.
     */
    double GetTxPowerW() const;

    /**
     * Set the transmission power of the modem.
     *
     * \param txPowerW Transmission power in watts.
     */
    void SetTxPowerW(double txPowerW);

    /**
     * Get the receiving power.
     *
     * \return The receiving power in Watts
     */
    double GetRxPowerW() const;

    /**
     * Set the receiving power of the modem.
     *
     * \param rxPowerW Receiving power in watts
     */
    void SetRxPowerW(double rxPowerW);

    /**
     *Get the idle power of the modem.
     *
     * \return The idle power in Watts
     */
    double GetIdlePowerW() const;

    /**
     * Set the idle state power of the modem.
     *
     * \param idlePowerW Idle power of the modem in watts.
     */
    void SetIdlePowerW(double idlePowerW);

    /**
     * Get the sleep state power of the modem.
     *
     * \return Sleep power of the modem in Watts
     */
    double GetSleepPowerW() const;

    /**
     * Set the sleep power of the modem.
     *
     * \param sleepPowerW Sleep power of the modem in watts.
     */
    void SetSleepPowerW(double sleepPowerW);

    /**
     * Get the current state of the modem.
     *
     * \return Current state.
     */
    int GetCurrentState() const;

    /**
     * \param callback Callback function.
     *
     * Sets callback for energy depletion handling.
     */
    void SetEnergyDepletionCallback(AcousticModemEnergyDepletionCallback callback);

    /**
     * \param callback Callback function.
     *
     * Sets callback for energy recharge handling.
     */
    void SetEnergyRechargeCallback(AcousticModemEnergyRechargeCallback callback);

    /**
     * Changes state of the AcousticModemEnergyModel.
     *
     * \param newState New state the modem is in.
     */
    void ChangeState(int newState) override;

    /**
     * \brief Handles energy depletion.
     */
    void HandleEnergyDepletion() override;

    /**
     * \brief Handles energy recharged.
     */
    void HandleEnergyRecharged() override;

    /**
     * \brief Handles energy changed.
     *
     * Not implemented
     */
    void HandleEnergyChanged() override;

  private:
    void DoDispose() override;

    /**
     * \return Current draw of device, at current state.
     */
    double DoGetCurrentA() const override;

    /**
     * \param destState Modem state to switch to.
     * \return True if the transition is allowed.
     *
     * This function checks if a given modem state transition is allowed.
     */
    bool IsStateTransitionValid(const int destState);

    /**
     * \param state New state the modem is currently in.
     *
     * Sets current state. This function is private so that only the energy model
     * can change its own state.
     */
    void SetMicroModemState(const int state);

  private:
    Ptr<Node> m_node;           //!< The node hosting this transducer.
    Ptr<EnergySource> m_source; //!< The energy source.

    // Member variables for power consumption in different modem states.
    double m_txPowerW;    //!< The transmitter power, in watts.
    double m_rxPowerW;    //!< The receiver power, in watts.
    double m_idlePowerW;  //!< The idle power, in watts.
    double m_sleepPowerW; //!< The sleep power, in watts.

    /** The total energy consumed by this model. */
    TracedValue<double> m_totalEnergyConsumption;

    // State variables.
    int m_currentState;    //!< Current modem state.
    Time m_lastUpdateTime; //!< Time stamp of previous energy update.

    /** Energy depletion callback. */
    AcousticModemEnergyDepletionCallback m_energyDepletionCallback;

    /** Energy recharge callback. */
    AcousticModemEnergyRechargeCallback m_energyRechargeCallback;

}; // class AcousticModemEnergyModel

} // namespace ns3

#endif /* ACOUSTIC_MODEM_ENERGY_MODEL_H */
